// ffmpegDecoder.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include <avcodec.h>
#include <avformat.h>
#include <windows.h>

#define FILE_NAME          "e:\\my\\test.flv"
#define OUTPUT_FILE_PREFIX "e:\\my\\image%d.bmp"
#define FRAME_COUNT        50

void SaveFrame(AVFrame *pFrame, int width, int height, int iFrame) {
  FILE *pFile;
  char szFilename[32];
  int  y;
  
  // Open file
  sprintf(szFilename, "frame%d.ppm", iFrame);
  pFile=fopen(szFilename, "wb");
  if(pFile==NULL)
    return;
  
  // Write header
  fprintf(pFile, "P6\n%d %d\n255\n", width, height);
  
  // Write pixel data
  for(y=0; y<height; y++)
    fwrite(pFrame->data[0]+y*pFrame->linesize[0], 1, width*3, pFile);
  
  // Close file
  fclose(pFile);
}

int _tmain(int argc, _TCHAR* argv[])
{
	AVFormatContext *pFormatCtx;
	int             i, videoStream;
	AVCodecContext  *pCodecCtx;
	AVCodec         *pCodec;
	AVFrame         *pFrame; 
	AVFrame         *pFrameRGB;
	AVPacket        packet;
	int             frameFinished;
	int             numBytes;
	uint8_t         *buffer;

	// Register all components
	av_register_all();

	// Open media file.
	if (av_open_input_file(&pFormatCtx, FILE_NAME, NULL, 0, NULL) != 0)
	{
		av_close_input_file(pFormatCtx);
		return 0;
	}

	// Get format info.
	if (av_find_stream_info(pFormatCtx) < 0)
	{
		av_close_input_file(pFormatCtx);
		return 0;
	}

	// Find the first video stream
	videoStream=-1;
	for(i=0; i<pFormatCtx->nb_streams; i++)
		if(pFormatCtx->streams[i]->codec->codec_type==CODEC_TYPE_VIDEO) {
			videoStream=i;
			break;
		}
	if(videoStream==-1)
		return -1; // Didn't find a video stream

	// Get a pointer to the codec context for the video stream
	pCodecCtx=pFormatCtx->streams[videoStream]->codec;
	
	
	// Find the decoder for the video stream
	pCodec=avcodec_find_decoder(pCodecCtx->codec_id);
	if(pCodec==NULL) {
		fprintf(stderr, "Unsupported codec!\n");
		return -1; // Codec not found
	}
	// Open codec
	if(avcodec_open(pCodecCtx, pCodec)<0)
		return -1; // Could not open codec

	// Allocate video frame
  pFrame=avcodec_alloc_frame();
  
  // Allocate an AVFrame structure
  pFrameRGB=avcodec_alloc_frame();
  if(pFrameRGB==NULL)
    return -1;
  
  // Determine required buffer size and allocate buffer
  numBytes=avpicture_get_size(PIX_FMT_RGB24, pCodecCtx->width,
			      pCodecCtx->height);
  buffer=(uint8_t *)av_malloc(numBytes*sizeof(uint8_t));
  
  // Assign appropriate parts of buffer to image planes in pFrameRGB
  // Note that pFrameRGB is an AVFrame, but AVFrame is a superset
  // of AVPicture
  avpicture_fill((AVPicture *)pFrameRGB, buffer, PIX_FMT_RGB24,
		 pCodecCtx->width, pCodecCtx->height);
  
  // Read frames and save first five frames to disk
  i=0;
  while(av_read_frame(pFormatCtx, &packet)>=0) {
    // Is this a packet from the video stream?
    if(packet.stream_index==videoStream) {
      // Decode video frame
//      avcodec_decode_video(pCodecCtx, pFrame, &frameFinished, 
//			   packet.data, packet.size);
      
      // Did we get a video frame?
//      if(frameFinished) {

	// Convert the image from its native format to RGB
//	img_convert((AVPicture *)pFrameRGB, PIX_FMT_RGB24, 
//                    (AVPicture*)pFrame, pCodecCtx->pix_fmt, pCodecCtx->width, 
//                    pCodecCtx->height);
	
	// Save the frame to disk
//	if(++i<=5)
//	  SaveFrame(pFrameRGB, pCodecCtx->width, pCodecCtx->height, 
//		    i);
//      }
    }
    
    // Free the packet that was allocated by av_read_frame
    av_free_packet(&packet);
  }
  
  // Free the RGB image
  av_free(buffer);
  av_free(pFrameRGB);
  
  // Free the YUV frame
  av_free(pFrame);
  
  // Close the codec
  avcodec_close(pCodecCtx);
  
  // Close the video file
  av_close_input_file(pFormatCtx);

	return 0;
}

